The Philadelphia 76ers have announced the signing of Shelvin Mack to a 10-day contract.In 14 games for the Maine Red Claws of the D-League this season, Mack averaged 20.5 points, 8.0 assists, 4.9 rebounds and 1.43 steals while shooting 46.2% from the floor, 41.8% from 3-point range and 89.6% from the line.Additionally, the 10-day contract guard Maalik Wayns signed on Jan. 8 has expired.